The present invention relates to trucks for railway vehicles and more particularly to an arrangement for keeping truck components aligned in a generally rectangular configuration during operation.
Railway vehicle trucks of the present invention comprise generally a pair of laterally extending and longitudinally spaced wheelsets, each set including an axle on each end of which there is mounted a wheel and a bearing assembly. The wheelsets are connected by side frames supported on the axles by bearing adaptors mounted on the axles. The side frames and the wheelsets are mounted on the underside of the railway vehicle car bodies in the conventional manner by way of bolsters resiliently supported adjacent each end on the laterally spaced side frames. Trucks of this general construction are conventionally known as four wheel trucks.
Such trucks have a tendency to hunt and yaw during normal operation of the railway vehicle along the track. To minimize such hunting and yawing, elastomeric devices have been interposed between the wheelsets and the side frames to restrain hunting and yawing by maintaining the wheelsets and the side frames in a generally ninety degree relationship to each other on nominally straight track while permitting limited restrained relative turning of the wheelsets and side frames when the trucks travel along curved tracks. Such elastomeric devices typically comprise an elastomeric pad bonded and sandwiched between a pair of metal plates. Typical structures of the prior art are shown in U.S. Pat. Nos. 3,638,582 and 3,381,629. Similar structures are also described in U.S. Pat. Nos. 4,416,203, 4,363,278 and 3,699,897.
Each of the prior art structures and arrangements were found to be unsuitable for general application to railway vehicles for the basic reason that the elastomeric pad failed to perform its intended functions.